Internal-combustion engine



Aug. 31, 1948. L. A. HOLAN ETAL INTERNAL-COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed June 5, 1946 Aug. 31, 1948. A H LAN ET AL 2,448,430

INTERNAL- COMBUSTION ENGINE Filed June 5, 1946 2 Sheets-Sheet 2 Jill/enters 41%fljwm/ Aiiorrzeys Patented Aug. 31, 1948 PATENT OFFICE INTERNAL-COMBUSTION ENGINE Leif A. Holan and Joseph 0. Bourdeaux, Minneapolis, Minn.;- said Bourdeaux assignor of one- Al'ipllcatioii June 3, 1946, Serial No. 873,982

sixth to said Holan 17 Claims. 1 This invention relates to internal combustion engines.

It is one of the objects of this invention to provide a novel, improved internal combustion engine having but relatively few moving parts and so constructed as to avoid the necessity for crank shaft, connecting rods, and numerous other parts found in the conventional internal combustion engine now in use.

Another object is to provide such an internal combustion engine wherein the pistons of the engine act as valves controlling intake and exhaust ports, thereby eliminating the necessity for the usual intake and exhaust valves and the attendant valve operating parts.

Another object is to provide an internal combustion engine having a piston chamber through which a plurality of pistons move successively through intake, compression, firing, and exhaust zones, movement of the pistons being so regulated that, as they pass through the intake zone there is a relative movement of adjacent pistons away from each other to cause a charge to be drawn into the intake zone and as. said pistons move through said exhaust zone, there is a relative movement of adjacent pistons'toward each other so as to expel the spent charge from the exhaust zone.

A further object is to provide in such an en-' gine as referred to in the last paragraph above, mean; for blocking off a portion of the chamber between the compression zone and the firing zone topermit of the compression of the charge in the compression zone and to permit of the firing of the charge in the firing zone, there being a by-pass passage between the compression zone and the firing zone controlled through movement of the pistons through said chamber.

A further object is to provide an internal combustion engine including a block having two circular piston chambers therein intersecting each other to form a common blocking zone, said chambers each having intake, compression, fire ing, and exhaust zones, and the common blocking zone. being located between the compression and firing zones of the two chambers, a plurality of pistons working through each of said chambers, means for supplying a combustible mixture to the intake zones, means for igniting the charges in the firing'zones, means permitting the exhaust of the spent charges from the exhaust zones said block having by-pass passages between the compression and firing zones of the respective chambers, and means for guiding the pistons of the two chambers therethrough in such relationship that, as the pistons work through said intake zones, they will act to draw a charge into the same, and as they work through said exhaust zones, they will act to scavenge the exhaust gases from the exhaust zones, the pistons of respective chambers working through said common blocking zone in alternation to make possible the compression of the charges and the firing of the charges in the respective chambers.

The objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the various views and in which:

Fig. 1 is a plan view illustrating an engine embodying the invention. Fig. 2 is a view in side elevation of the engine. 20 Fig. 3 is a vertical section taken on the line 3--3 of Fig. 1 as indicated by the arrows.

Fig. 4 is a horizontal section taken on the line 4-4 of Fig. 3 as indicated by the arrows.

- Fig. 5 is a horizontal section taken on the line 2 5-4 of Fig. 3 as indicated by the arrows, Figs. 3, 4, and 5 being shown in enlarged scale relative to Figs. 1 and 2; and v Figs.' 6, 7, 8, and 9 are diagrammatic views showing the positions that the pistons of the engine will take in the piston chambers during the initial periods oi'intake, compression, firing, and exhaust, respectively, of a single charge.

.As the invention is shown in the illustrated embodiment, the block B of the engine is of substantially cloverleaf shape in plan view and includes several individual block sections, among which are what may be called external piston block section Ill, two internal piston block sections ll, upper and lower seal block sections l2, and upper and lower cap block sections I 3.

The external and internal piston block sections I0 and II cooperate to form the side walls of two circular piston chambers designated reof an external wall of these chambers and the II. The two internal piston block sections ii i w have stems lib which project above and below the main portions of the blocks ii and fit at their ends within recesses formed in the cap block sections ii. The block sections, i3. i2, and ll are secured together as by nutted bolts I and the internal piston block sections H are secured in place as by means of bolts ll running through the cap block sections it and secured in tappedopenings formed in the stems lib.

Thev arcuate pistons II, which work through the two piston chambers in and As, offcourse revolve about axes from which the two chambers A1 and A: are respectively evolved. Rotatin about axes parallel to but eccentric to the axes about which the pistons i5 revolve are upper and lowerpiston guiding rotors II for each piston chamber A1 and A2, and these rotors II are preferwhich mesh with the vertically aligned gears it 4 5, the guide slots Ila of the rotors it working in conjunction with one of the chambers Ai are set sixty degrees ahead of the guide slots ila of the rotors, working in conjunction with the other cylinder A2. Also it shouldbe noted that in the illustrated embodiment the axes of rotation of the rotors ii are in the same plane as the axes about which the pistons rotate but the axes of rotation of the rotors are respectively eccentrically offset outwardly from the respective axes of rotation of the pistons i5 relative to the common zone C of the two chambers Ar and A2.

A drive shaft 24 extends through and is journalled in the block B. for rotation about an axis parallel to the axes of rotation of the gears IO, and this shaft carries upper and lower gears 2!,

at one'side of the engine but do not meshwith the gears I. at the other side of the engine. The

0 gears '25 fit within recesses in the cap block ably formed integrally respectively with upper and lower gears it, the two upper gears inter-- meshing with each other and the two lower gears intermeshing with each other. To receive the combined rotors II and gears it, the cap block sections [3 are recessed and equipped with bosses .ila, the gears I! riding on bearings, such as the anti-friction ball bearings 20, interposed between the bosses Ila and the gears It. The seal block sections [2 are apertured to receive the rotors l8 and the rotors are grooved at their edges to carry seal rings M, which fit within the apertures in the seal block sections i2 and bear against the internal walls thereof whereby the rings 2| working in conjunction with the pistons ii, the rotors i8 and the seal block sections l2 seal oil the open tops and bottoms of the piston chambers A1 and A2.

The pistons I! have, projecting from their tops and bottoms at their central portions, pins 22,

the axes of which are either in line with or inwardly disposed from the inner surfaces of the pistons taken toward the central axes about which the pistons revolve, and the inward offsetting of these pins 22 is for the purpose of permitting suflicient longitudinal movement of the pins 22 relative to the rotors II as will presently appear. The pins 22 carry above and below the adjacent seal block sections i=2 bearings, such as the anti-friction ball bearings, 2I,which work within guide slots Ila radially cut at equal circumferentially spaced intervals in the piston guiding rotors l8. With this arrangement it will be seen that, as the pistons i5 revolve in the piston chambers A1 and As, the respective rotors II will control the spacing between the pistons working in the respective chamber A1 or A: and that the piston pins 22 may have a movement inwardly and outwardly, along radial lines relative to the centers of rotation of the rotors II. In the particular engine illustrated, there are three pistons it working in each chamber A1 and A1, and accordingly there are three guide slots "a formed in each rotor It. The upper and lower pairs of gears is are so meshed together for tun ing purposes of the pistons working through the two chambers A1 and A: that, as best seen in Fig.

sections i3. 7

Each piston chamber Ai and A: has an intake zone a, a compressionzone b, the zone c which may be referred to as a blocking zone and which is common to both chambers, a firing zone d, an an exhaust zone e, and the pistons ii travei through these various zones in the order in whic they are named. The limits of these different zones are indicated by brackets, Fig. 4, adjacent the letters designating these zones. There is pro vided a fuel intake manifold 22, which has two branches secured to the upper cap block section I3, and the branches of the intake manifold communicate with intake passages 21 running through the upper cap block section II and the -respective internal piston block sections Ii and communicating with intake ports 2! running through the walls of the respective internal piston block sections II and communicating with the o intake zones a ofthe two chambers A1 and A2.

A combustible fuel mixture is adapted to be supplied in conventional manner as by means of a carburetor (not illustrated) to the intake manifold 28. Affording communication between the piston exit ends of the compression zones b and the piston entrance ends of the firing zones d of the respective chambers are by-pass passages 2| running respectively through the respective internal piston block sections ii, these by-pass pas sages 29 being preferably quite narrow at their ends where they communicate with the chambers A1 and A: for rapid control of the same by the pistons i5 and being preferably widened but re-.' duced in height intermediate their ends, as best shown in Figs. 3 and 4. The by-pass passages 29 bridge the space formed by the common blocking zone 0 of the two piston chambers to at times convey the compressed charges from the compression' zones b to the firing zones d without passing through the common blocking zone 0.

To ignite the compressed charges in theflring zones d the external piston block section i. may be bored and tapped to receive spark plugs 32 Y 'having direct communication with the firing guano s the internal piston block sections i I and the lower cap block section it and communicating with a two-branched exhaust manifold 34 from which the spent gases may be discharged.

Operation Each plug ll for the two piston chambers A1 and A: will be timed to lire just after the rear end of each piston ll, working in the chamber for which the lug is employed, has moved past the outlet end of the adjacent by-pass passage II. As the engine is placed in operation, the pistons in piston chamber A1 will rotate in a counterclockwise direction as viewed in Figs. 4 and 5, while the pistons in piston chamber A: will rotate in a clockwise direction. As the pistons ll .revolve in, one of the piston chambers, a relative movement between adjacent pistons will be produced due to the guiding action of the piston guiding rotors II, this relative movement being such that adjacent ends of adjacent pistons will move away from each other in the intake zone a and they will move toward each other in the exhaust zone e. The spacing between the adjacent ends of adjacent pistons ll working within a single chamber A1 or A: gradually increases through the intake zone a and the compression zone b from a very closely spaced relation at the entrance end of the intake zone .0, until the pistons reach their greatest spacing inidway of the common blocking zone 1:. Similarly the spacing between adjacent ends of pistons gradually decreases as the pistons work through the firing zone d and the exhaust zone e. The pistons. as they move through one of the piston chambers, have a valve action to alternately open and close fuel intake ports ll, the entrance-ends and discharge ends of the by-pass chambers", and'the exhaust ports 32. As a piston ll,;;working within the right-hand chamber A1 for example, moves through the common blocking zone 0. it seals and blocks the passage of the compressed charge from the compression zone b of the left-hand chamber A: through the common blocking zone to the firing zone d of the chamber A5. In similar manner, the pistons, working in the left-hand chamber A: and successively running through the common blocking zone c, block oil! communication in the righthand chamber A1 from the compression zone b through the common blocking zone 0 to the liring zone it. At the time the pistons in one chamber work through the common blocking zone c, the adjacent pistons of the other chamber are spaced far enough apart so that the pistons of 1 the first chamber will not collide with or interning to be drawn into the intake zone a of the right-hand piston chamber A1- between the No. 1 piston and the No. 3 piston. As the pistons rotate from the position shown in Fig. 6, the piston 1 draws away from the piston 3 to suck in a charge through the intake port 2| of the chamber Ar. Thereupon the pistons rotate to the position shown in Fig. 'I, that is, to a point where piston 1 has moved through the common blocking zone 0 .the No. 3 piston and the No. 2 piston. and of course the entrance to the by-pass passage-29 for the right-hand chamber A1 is open inasniuch as the No.1 piston has moved past this entrance. The outlet of this same by-pass chamber '2! is closed by the No. 1 piston. As the pistons now continue to rotate beyond their position as shown in Fig. '1, the recently drawn-in charge in chamber A1 is compressed due to the movement oi the No. 3

' piston toward the No. 2 piston. This "compressed charge is forced into the right by-pass chamber 2! through the entrance thereof, and the charge cannot escape from this by-pass chamber until after the No. 1 piston has moved past the outlet of the said by-pass passage 28 or to the firing position shown in Fig. 8. the No. 1 piston now moves past the outlet of; the by-pass passage 2! for the chamber A1, the rlo. 3 piston closes the intake to the right by-pass passage 2! and the compressed charge is admitted to the small space now formed, as shown in Fig.

8, between the rear end of the No. 1 piston and the bio. 2 piston, which occupies the major portion off the common blocking zone c. As the parts niove to the position shown in Fig. 8', the spark plug III for the chamber A1 fires to ignite the cofiipressed charge filling the by-pas'spassage 2! of'chamber A1 and the space between the rear v end of piston l and piston 2. As the compressed charge is ignited by the spark from the said plug 3|, the charge explodes and reacts between the piston 2 and the rear end of the piston 1 to drive the piston ahead. The power transmitted hy the explosion of'the charge to the piston l is in turn transmitted from this piston through the pins 22 carried thereby to the right-hand piston guiding rotors ll whereby all the movable parts ofi'the engine are driven.

"The pistons then continue to revolve in their cylinders until they have reached the exhaust position shown in Fig. 9. As they arrive at this position, the forward end of No. 3 piston is just emerging from the common blocking zone 0 and the rear end of the No. 1 piston is jiist beginning to. expose the exhaust port 32 for the chamber A At this time there is a relative movement of the forward end of the piston it, toward the rear end of the piston l, and this relative movement forces the spent exploded gases through the right-hand exhaust port 32 to scavenge the exploded charge from the chamber Ari The parts then again move to the intake position shown in Fig.5, whereupon a new cycle of operation commences. f

- Through each complete revolution of the various pistons through their respective chambers Ar and A2, six complete cycles or operation will be accomplished: in other words, six charges will be taken in, compressed, fired, and exhausted so that during each complete revolution six power strokes will be imparted. In other words, while the pistons 2, 4, and 6 of the chamber A: coact with the'pistons 1, 3, and 5 of the chamber A1 to produce three power strokes, in like manner the pistons l, 3, and 5 of the chamber A1 coact with the pistons 2, 4, and 6 of the chamber A: to produce three power strokes in this chamber.

It should be noted, as best shown in Fig. 3,

that, after a, charge has been fired, for example, the charge between the piston 2 and the rear end of the piston 1, the piston 2 seals the blocking zone 2 until such time as the piston 1 has moved to expose the exhaustport 32 for the right-hand chamber Ai. It is quite important that the piston 2 remains in the blocking zone 4; until the exhaust port 32 opens, inasmuch as if the piston 2 emerged from the blocking zone before the exhaust port 82 opened the reactive force of the exploded charge would work against the forward end of the piston 3 tending to cause the pistons of the right-hand chamber to. turn in a clockwise direction instead of a counterclockwise direction and producing back pressure. Actually in the illustrated embodiment, the exhaust ports extend throughapproximately 97 .of the chambers Ai and A: while the intake ports 28 extend through approximately 79 to 80, and while the length of the ports can be varied in relation to the circular piston chambers A1 and A2, care must be taken that the exhaust ports of one chamber open simultaneously with or just ahead of the time of the unblocking of the common zone 0 by a piston working within the other chamber.

Now, referring back again to Figs. 1 to 5 of the drawings. asa charge is fired, the power that is applied to the piston I! of the energized piston is transmitted through the two pins 22 of that piston and the bearings 23 attached to these pins to the particular piston guiding rotors II with which the said bearings 13 of that particular piston engage,- The right and leftrotors ll, being attached to or integrally formed with the gears It at that side of the engine, transmit power to the gears, and as the two gears i! at one side of the engine engage with the two gears I! at the other side of the engine and two of the gears I! at one side of the engine engage with the gears 25 of the drive shaft 24, power is transmitted to the drive shaft. Due to the fact that duplicate pins 22, rotors l8, gears l8, and gears 15 are provided at both the upper and lower portions of the engine, the power stroke is applied evenly and without torque, thereby unevenly distributing the power to the moving parts. As six power impulses are given to the engine during each complete revolution of the pistons I! through their respective chambers A1 and As, the power is very evenly applied so that a very smooth running engine is secured. Actually the power-strokes are practically continuous as the engine is in operation.

To simplify the drawings, the lubrication and cooling systems for the engine are not shown. but in actual practice suitable lubrication and cooling systems will be provided. To multiply the power desired applied to a given drive shaft 24, it is merely necessary to duplicate the engine illustrated, placing the several engines in line and operating the same drive shaft from the multiplicity of engines. Preferably of course where multiple engines are employed, the timing of the respective engines will be so regulated as to stagger the power strokes of the several engines producing greater smoothness in the application of power.

It will be .seen that a highly efflcient engine has been provided which includes but very few moving parts and eliminates the use of a crank shaft, connecting rods, wrist pins, ,cam shaft, cams, exhaust and intake valves, and exhaust It will alsobe seen that a highly compact engine has been provided which will develop a high degree of power with a minimum of weight.

It will of course be understood that various changes may be made in the form, details, arrangement, and proportions of the various parts without departing from the scope of the present invention, which, generally stated, consists in the matter shown and described and set forth in the appended claims.

What is claimed is: 1. An internal combustion engine comprising a block having an annular chamber, a plurality iof pistons located within said" chamber for rotation therein, means for intermittently blocking an a zone of said chamber between adjacent pistons,

guiding means driven by the pistons and guiding the pistons as they rotate to cause a timed relative movement between adjacent pistons in such manner that adjacent pistons draw apart as'they approach said zone and draw together as they recede from, said zone, there being a by-pass passage'through said block affording communication between portions of said chamber adjacent the ends of said zone, means supplying a combustible mixture to said chamber at a portion thereof wherein adjacent 'pistonsf draw apart, means forv conducting exploded gases from said chamber-at a portion thereof wherein adjacent pistons draw together, means for igniting a charge in said chamber at a point just beyond said zone and a member in turn dniven by said guiding means.

' '2. An internal combustion engine comprising a block provided with a circular piston chamber having intake, compression, blocking, firing, and exhaust zones, a plurality of pistons working in said chamber through the zones therein in the sequence in which said zones are named, said block having a by-pass passage running between the piston exit end of said compression zone and the piston entrance end of said firing zone, means for supplying a combustible chargeto said intake zone, means for igniting the charge in the firing none, means for conducting the spent charge from said exhaust zone, and means operated by v said pistons and causing relative movement between adjacent pistons as they move through said chamber in such manner that as adjacent pistons: move throughysaid intake zone they willmove away from each other and as adjacent pistons move through said exhaust zone they willinove toward each other and means for intermittently blocking said blocking zone between the adjacent ends of adjacent pistons;

3. An internal combustion engine comprising a block provided with a circular piston chamber having intake, compression, blocking, firing, and exhaust zones, a plurality of pistons working in said chamber through the zones .thereinin the sequence in which said zones are named, said block having a by-pass passage running between the piston outlet end of said compression zone and the piston entrance end of said tiring zone, means for supplying a combustible charge to said intake zone, means for igniting the charge in the firing zone, means for conducting the spent charge from said exhaust zone, and means driven by said pistons and rotating about an axis taken and intake ports employed in engines of standard construction today.

movement away from each other, and as said pistons move through said exhaust zone the adjacent ends of adjacent pistons will have a relative movement toward each other, and means for intermittently blocking said blocking zone intermediate the adjacent ends of adjacent pistons.

4. The structure defined in claim 3, said blocking means comprising a series of secondary pistons driven in timed relation with the pistons moving through said chamber, said secondary pistons intermittently moving through said blocking zone in alternation with said first mentioned pistons.

5. An internal combustion engine comprising a block having an annular piston chamber therein, divided into intake, compression. blocking, firing, and exhaust zones, pistons working through said chamber in the sequence in which said zones are named, means operated by said pistons and guiding the movement .01. said pistons through said chamber to cause a relative movement of adjacent pistons away from each other as they travel through said intake zone and toward each other as they travel through said exhaust zone, said chamber having an intake port for introducing a charge into said intake zone and having an exhaust port for scavenging the spent charge from said exhaust zone, means for igniting the charge in said firing zone, said block having a by-pass passage having a receiving end leading into said chamber in said compression zone and a discharge end leading into said chamber in said firing zone, said pistons acting as valves to control said intake port, receiving and discharge ends of said by-pass passage and said exhaust port, and means for blocking oif said blocking zone in alternation with movement of the pistons therethrough.

6. The structure defined in claim 5, a gear driven by said guiding means, and a power shaft driven by said gear.

7. The structure defined in claim 5, said guiding means including a rotor rotating about an axis parallel and eccentric to the axis about which said chamber is evolved, said rotor having guide slots, and members carried by said pistons and working in said slots.

8. An internal combustion engine comprising a block having a circular piston chamber forming an intake zone, a compression zone, a blocking zone, a firing zone, and an exhaust zone, a plurality of pistons working in said chamber through the zones thereof in the sequence in which said zones are named, said block having a by-pass passage running between the piston exit end of said compression zone and the piston entrance end of said firing zone, means for supplying a combustible charge to said intake zone, means for igniting the charge in said firing zone, means for conducting the spent charge from said exhaust zone, a rotor mounted for rotation about an axis eccentric and parallel to the axis about which said circular piston chamber is evolved, said rotor having radial guide slots within which portions of said pistons work to produce a relative movement of said pistons as they rotate in said piston chamber in such manner that adjacent pistons move apart as they pass through said intake zone and adjacent pistons move toward each other as they pass through said exhaust zone, a member working through said blocking zone and means for operating said last mentioned member in timed sequence with the movement of said pistons through said blocking zone and in such manner that said last men- 10 tioned member occupies the major portion of said blocking zone when said pistons do not occupy the same.

9. An internal combustion engine comprising a block having two circular piston chambers therein intersecting each other to form a common blocking zone, each chamber having intake, compression, firing, and exhaust zones and the common blocking zone of the two chambers being located between the compression and firing zones of the respective chambers, said block having bypass pass-ages respectively interconnecting the compression and firing zones of each chamber, piston regulating means receiving power iron: said pistons and controlling the movement 01' said pistons in such relation that the pistons working in the respective chambers alternately pass through said common blocking zone and the pistons in each chamber are given a relative movement' to each other as they rotate so that adjacent pistons move away from each other as they pass through said intake zones and move toward each other as they move through vsaid exhaust zones, means for supplying a combustible mixture to said intake zones, means (for igniting the charge in the firing zones, and means for conducting the spent charges irom said exhaust zones.

10. An internal combustion engine comprising a block having two circular piston chambers therein intersecting each other to form a common blocking zone, each chamber hlaving intake, compression, firing, and exhaust zones and the com-mon blocking zone of the two chambers being located between the compression and fining zones of the respective chambers, said block having bypass passages respectively interconnecting the compression and firing zones of each chamber, piston guiding means for each chamber respectively mounted for rotation about an axis parallel and eccentric to the axis about which its circular piston chamber is evolved, said guiding means receiving power from the pistons while guiding the pistons in such relation that as the pistons work through the intake zones the ladjacent ends of adjacent pistons will have a relative movement away from each other and as the pistons work through the exhaust zones adjacent ends of adjacent pistons will have a. relative movement toward each other, and means causing said guiding means to be driven together in unison in such timed relation that the pistons of the two chambers work in alternation through said common blocking zone to alternately seal ofl communication between the compression zone and the firing zone of one chamber when a piston working in the other chamber passes through said common blocking zone,

means for supplying a combustible to the intake zones, means rfor igniting the charges in the firing zones, and means tor conducting the spent charges from said exhaust zones.

11. The structune defined in claim 10, said guiding means including pins carried by said pistons and rotors having radial slots therein and respectively receiving the pins carried by the pistons working in the respective chambers.

12. The structure defined in claim 10, said chambers each having at least one side open, and sealing means .working in conjunction with said pistons, \and said guiding means to seal of! the open sides of said chambers.

I 13. An internal combustion engine comprising a block having two circular. piston chambers therein intersecting each other to form a com- 11* rnon blocking zone, each chamber having intake, compression, firing and exhaust zones and the common blocking zone of the two chambers being located between the compression and fining zones 0,! the respective chambers, said block having bypass passages respectively interconnecting the compression and firing zones of each chamber, aplu-ralityof pistons in each chamber mounted for rotation therein, pins carried by said pistons, rotors having guide ways receiving said pins and controlling the movement of said .rpistons in the respective chambers so that, as said pistons pass through said intake zones, adjacent pistons move away from each other, and as said pistons move through said exhaust zones, adJ-acent pistons move away from each other, means calming said rotors to be driven in unison in such timed re- 7 ablock having a pair of circular piston chambers therein intersecting each other to form a common blocking zone, each chamber having intake,com-

16. The structure defined in claim 14 and means sealing oi! said chambers at their sides.

17. An internal combusition engine comprising a block having two circular piston chambers therein intersecting each other to form a common blocking zone, each chamber having intake, compression, firing, and exhaust zones, and the common blocking zone of the two chambers being located between the compression and firing zonesof the respective chambers, pistons working through said chambers rotating about the axes from which said chambers are evolved rotors respectively for the pistons of each chamber, said rotors being mounted in-sa'id block for rotation about axes parallel and eccentric to the axes about which said pistons revolve, said rotors having guide ways therein, members carried by saidpistons and working in the guide ways of said rotors,'the axes. of said rotors being so locatedthat, as said pistons move through said chambers, said cam tracks will cause a relative movement of adjacent pistons away from each other as they. pass through said intake zones and'toward 'each' other as they pass through said exhaust zones said chambers having intake ports for introducing charges into said intake zones and having exhaustports for scavenging the spent chargesirom said.

pression, firing, and exhaust zones, and the com- 4 mon blocking zone 01' the two chambers being located between the compression and firing zones or the respective chambers, pistons working through said chambers, -guiding means driven by said pistons and guiding the movement of said pistons through said chambers to cause a relative movement of adjacent pistonsaway from each other as they pass through said intake zones and toward each other as they pass through said exhau'st zones, said chambers having intake ports for introducing charges into said intake zones and having exhaust ports for scavenging the spent charges from said exhaust zones, means for igniting the charges in saidfiring zones, said block having by-pass passages having receiving ends leading-into said chambers in said compression zones and discharge ends leading into said chambers in said firing zones, said pistons acting as valves to control said intake ports, the receiving and discharging ends of said by-pass passages and said exhaust ports and means causing said guiding means to be driven together in such timed relation that successive pistons in the two chambers alternately work through said blocking zone. I

15. The structure defined in claim 14, said last mentioned means comprising intermeshing gears operated by said guiding means, and a drive shaft driven by certain of said gears.

exhaust zones, means forigniting the charges insaid' firing zones, said block having by-pass passages having receiving ends leading into said chambers in said compression zones and discharge ends leading into said chambers in said firing zones, said pistons acting as valves to control said intake ports, the receiving and discharge ends of said by-pass passages and said exhaust ports and means causing said rotors to be driventogether in such timed relation that successive pistons in the two chambers alternately wor through said common blocking zone. I

. LEIF A. HOLAN.

JOSEPH o. BOURDEAUX.

REFERENCES CITED The following references are file of this patent:

UNITED STATES PAT NTs of record in the 

